Related Experiment Video

Updated: Aug 18, 2025

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
06:56

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli

Published on: March 24, 2023

5.7K

Examination of the horizontal gene transfer dynamics of an integrative and conjugative element encoding multidrug

Mai Farghaly1, Michael F Hynes2, Mohammad Nazari1

  • 1Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.

Canadian Journal of Microbiology
|December 10, 2022
PubMed

Insights

Integrative and conjugative elements like ICEHs02 spread antimicrobial resistance genes between bacteria. This study shows antimicrobial stressors increase ICEHs02 transfer, but its acquisition reduces bacterial fitness.

Area of Science:

  • Microbiology
  • Genetics
  • Molecular Biology

Background:

  • Integrative and conjugative elements (ICEs) are key drivers of antimicrobial resistance (AMR) dissemination in bacteria via horizontal gene transfer.
  • ICEHs02, a 72,914 bp ICE from *Histophilus somni*, carries seven predicted AMR genes, including resistance to tetracycline, florfenicol, sulfonamides, and aminoglycosides.
  • Understanding ICE host range, transfer dynamics, and host fitness effects is crucial for combating AMR.

Purpose of the Study:

  • To investigate the host range of *ICEHs02*.
  • To assess the impact of antimicrobial stressors on *ICEHs02* transfer frequency.
  • To examine the effects of *ICEHs02* acquisition on host bacterial fitness.

Main Methods:

  • Conjugation assays were performed to determine *ICEHs02* transfer frequency between *H. somni* and *Pasteurella multocida* strains.
  • Polymerase chain reaction (PCR) confirmed the presence of ICE-associated core and cargo genes in recipient strains.
  • Antimicrobial susceptibility testing evaluated resistance phenotypes in transconjugants; fitness was assessed using relative fitness assays.

Main Results:

  • Tetracycline and ciprofloxacin significantly increased *ICEHs02* transfer rates *in vitro*.
  • Antimicrobial induction led to substantial increases in the copy number of the *ICEHs02* circular intermediate.
  • *ICEHs02* acquisition reduced the relative fitness of *H. somni* transconjugants by 28% and *P. multocida* transconjugants by 15%.

Conclusions:

  • Antimicrobial stressors can enhance the horizontal transfer of *ICEHs02*, potentially accelerating AMR spread.
  • While conferring resistance, *ICEHs02* acquisition imposes a fitness cost on host bacteria.
  • This study provides insights into the mobile genetic element dynamics contributing to bacterial adaptation and AMR evolution.
Keywords:
Histophilus somniantimicrobial resistancehorizontal gene transferintegrative and conjugative elementsmetal tolerance

More Related Videos

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

16.7K
Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation10:41

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

13.9K

Related Concept Videos

Conjugation01:19

Conjugation

Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
57
Horizontal Gene Transfer01:27

Horizontal Gene Transfer

Horizontal gene transfer (HGT) is a process where genetic material moves between organisms within the same generation, unlike vertical gene transfer, which occurs from parent to offspring. HGT plays a crucial role in microbial evolution, adaptation, and survival, particularly in shared environments like the human gut.Mobile genetic elements such as plasmids, prophages, integrons, insertion sequences, and transposons facilitate this process. HGT occurs through three primary mechanisms:...
66
Transduction01:16

Transduction

Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
69
Mechanism of Conjugation01:19

Mechanism of Conjugation

Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
86
Types of Genetic Transfer Between Organisms02:18

Types of Genetic Transfer Between Organisms

Genetic transfer occurs when genetic information is passed from one organism to another. It occurs via two mechanisms: vertical gene transfer and horizontal gene transfer. Vertical gene transfer occurs when genetic information is transferred from one generation to the next, which happens much more frequently than horizontal gene transfer. Both sexual and asexual reproduction are forms of vertical gene transfer, where one or more organisms pass some or all of their genome onto their progeny.
29.1K
Transposons01:24

Transposons

Transposons, or "jumping genes," are small mobile genetic elements (MGEs) that range from 700 to 40,000 base pairs in length. They are found in all organisms and can move within the same chromosome or transfer to different chromosomes. In some cases, transposons can also jump between different host DNA molecules, such as plasmids or viruses, contributing to genetic variability.Barbara McClintock first discovered these mobile genetic elements in the 1940s while studying maize genetics, and she...
97